Do I need to remove the existing 1 ceramic tiles in the shower stall, or can I apply the new 8 ceramic tiles right on top of the old ones? The sides are drywall, but the floor of the stall has 1 tiles that look like a pain to remove.
A sublayer of tiles will be a very poor foundation for the new layer. In short, don't ever try to find shortcuts in construction. They never work. Always go ahead and do the work properly.
The reason 1 tiles were used in your shower base is to achieve the slope neccesary for the water run-off to the drain. You will be hard-pressed to accomplish this with 8 tiles. You can adhere new tile to old with epoxy-based mastic, but I would recommend consulting with a pro to get your water properly emptying into the drain.
Actually you can. But it involves some risk. There are many cases in which the new tiles does not stick or they will fall after some time. It is better to remove the old tiles.
You can use the 8 tiles on the walls of the shower. However, the floor of the shower must slope into the drain. The 8 tiles will not allow the slope to be created properly. If you etch or clean the floor tiles with an acid solution (muriatic acid) you can lay new tiles over them with thinset. However, it is much better to pull the floor tiles up, repair the drain pan if necessary, and install new tiles. You may want to hire a pro for the floor and then do the walls yourself. Good Luck.
First off, I would not put 8 ceramic tiles in a shower. (Unless you have a huge shower that can support 15 people or more, and even then, they use the 'one inch' squares... 8' tiles are not meant for showers. They are meant for applications of flooring, outside the tub or shower. (You cant slope them as needed for a shower or hot tub as the one inch ones). Also, I would never lay them down, for fear of cracking them! The small tiles can expand and contract, with the different heat of the water, while the large ones will not. They will be laying on a base of something that 'IS still expanding and contracting, even if you could clean the tiles off, sufficiently enough, (with an acid product), to remove all the soap and grime and grease and all the matter so that the mastic will stick to the individual tiles... Now, you could take the one inch tiles off, (they are laid down in rows, of either 6X6 or 12X12 inch sections, I forget which it is now...sorry). Get a cold chisel and some goggles and knee pads and go to work, chipping the tiles up... (once you get a few, they wll start to pop up real quick like). Then, try and bust out as much grout as you can, and even use a grinder if you need to, to get the rest, but, have your exhaust fan going in the bath room, and a fan blowing to give fresh air...possibly a window open and a fan blowing out, to carry the dust out...also a good respirator, so you dont get the dust into your lungs! I wish you well Jesse
